Dry Eye Dx and Tx

The Hormone-Dry Eye Connection, Part 1

BY WILLIAM TOWNSEND, OD, FAAO

Sex hormones have a long-recognized impact on tear production and ocular surface health (Rocha et al, 2013). More recently, research has also exposed the influence of non-sex hormones on the ocular surface, particularly in regard to tear production (Gadaria-Rathod et al, 2013).

A recent study reported that androgens regulated the expression of more than 3,000 genes in human meibomian gland and conjunctival epithelial cells (Khandelwal et al, 2012).

In a study comparing males and females who had non-autoimmune MGD to normal controls, individuals who had MGD showed significantly reduced levels of three androgens: bioactive testosterone, dehydroepiandrosterone (DHEA), and DHEA sulphate, suggesting that androgen deficiency in both males and females contributes to MGD (Tamer et al, 2006).

There is ample evidence that thyroid-associated ocular surface changes also involve pathological thyroid hormone (TH) levels. In an animal model, Dias et al (2007) evaluated the location and comparative expression of thyroid hormone receptor-1 (Thrb) in the lacrimal glands (LG) of rats with hypothyroidism (HT) and in controls. They found that lacrimal gland weight and T4 (free and bound) was reduced, and noted up-regulation of Thrb, attributed by the authors to chronic TH deprivation. Schirmer test results showed a greater than two-fold reduction in tear production in hypothyroid versus controls. CLS

For references, please visit www.clspectrum.com/references.asp and click on document #218.

Dr. Townsend practices in Canyon, Texas, and is an adjunct professor at the University of Houston College of Optometry. He is president of the Ocular Surface Society of Optometry and conducts research in ocular surface disease, lens care solutions, and medications. He is also an advisor to Alcon, B+L, CooperVision, Tearlab Corporation, and Vistakon. Contact him at drbilltownsend@gmail.com.